Implant implantation unit

ABSTRACT

The implant implantation unit, at a determined position in the tubular element with a wall comprising a cavity, is pushed there by a catheter and the unit comprises deformable feelers to, under the control of remote activation elements, change from a stowed form to a deployed functional form, to detect the cavity and position itself there with reference to the position of the cavity.

This application is a continuation of U.S. application Ser. No.10/210,085, filed on Aug. 2, 2002, now abandoned, which is incorporatedherein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The current invention relates to an implant implantation unit and to aprocedure for fitting the unit in a tubular element.

The problem at the origin of the invention concerns the implantation ofheart valves. Until recently this necessitated open heart surgicaloperations, with stages such as stopping the heart, the implementationof extra bodily blood circulation and restarting the heart after theimplantation of replacement heart valves. These surgical operations aredifficult and delicate and present mortal risks related to operatingshocks.

2. Description of Related Art

Document U.S. Pat. No. 5,824,063 thus describes a unit carryingreplacement heart valves, the unit comprising a tubular implant insynthetic material carrying internally a replacement valve in naturalmaterial.

Documents U.S. Pat. No. 5,855,601 and U.S. Pat. No. 5,868,783 describenew heart valve implantation methods, which offer the advantage ofavoiding open heart surgery. These methods provide the implantation, bymovement through the blood circulation system, of a heart valvereplacement unit comprising a radially expandable intra-vascularcylinder carrying a biological valve internally. An inflatable part of aballoon catheter is placed inside the carrier cylinder and theimplantation is done by introduction into a vein and movement as far asthe failed valve using a catheter. A two dimensional image screendisplay allows the detection that the carrier cylinder has reached therequired position and the cylinder is then dilated by inflating theballoon through the catheter and maintains its expanded shape. Theballoon is then deflated and withdrawn with the catheter.

The carrier cylinder presents a sealed casing, which is thus forcedagainst the artery wall, so as to avoid the blood flow bypassing thereplacement valve.

However, when the aorta is involved this procedure is not applicablebecause the coronary arteries open close to the failed native valves, sothat the carrier cylinder is likely to block them, provoking the deathof the patient.

BRIEF SUMMARY OF THE INVENTION

The inventors of the present application have therefore thought ofproviding two corresponding openings in the wall of the carrier cylindercasing. However, so that these openings will be placed opposite the twocoronaries, the position of the carrier cylinder in the aorta must becompletely controlled. Monitoring on the screen allows the progress, oraxial position, of the carrier cylinder to be checked, but the angularposition will be neither visible nor controlled.

The applicants have therefore found a solution, described below,allowing the position of the carrier cylinder to be controlled.

They have therefore thought about the resolution of the more generalproblem of positioning an implant unit or transport vehicle in a tubularelement with difficult access and for which imaging is insufficient oreven impossible. The field of application could thus concern otherfields than the medical, such as the petroleum or nuclear industries,for installing sensors, valves and other items. The scope of the presentapplication must therefore not be considered as limited to theresolution of the original problem. In a more general way, the inventionaims to allow, the placing, in a difficult to access location of atubular element, of a unit intended to carry an implant, whatever thefunction of the implant.

To this end, the invention concerns in the first place a unit for theimplantation in a determined position of a tubular element with a wallcomprising a cavity, the unit being arranged to cooperate with means fordriving the unit in the tubular element, a unit characterized by thefact that it comprises deformable feelers arranged so that, under thecontrol of means for remote activation, it passes from a stowed to adeployed functional shape, to detect the cavity and position itselfthere with reference to the position of the cavity.

Thus, the unit can be made to advance blind and the feelers allow theautomatic detection of the cavity and positioning at it.

The final required position can also be reached even through acontraction of the tubular element for example an access artery leadingto an artery of larger diameter.

The invention also concerns a process, which is not surgical and withouttherapeutic aim, for implantation of the inventive unit, at apredetermined position in a tubular element presenting a wall comprisinga cavity which procedure is characterized by the fact that

a user inserts the unit through an open end of the tubular element

he activates drive means to make the unit advance to a position beforethe determined position,

he commands the feeler remote activation means and, with the advancecontinuing,

he stops the action of the drive means when he detects a blockage of theadvance, indicating that the feeler means are positioned in the cavity.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The characteristics and advantages of the present invention will appearmore clearly with the aid of the following description of a particularform of the realization of the inventive unit and a variant, as well asthe procedure for using it, with reference to the attached drawing, inwhich:

FIG. 1 is a lateral cross section of the inventive unit, representingthe feeler positioning and anchoring elements, associated with acylinder carrying a valve prosthesis, the whole being covered by tworemovable concentric activation casings,

FIG. 2 corresponds to FIG. 1, the feeler positioning and anchoringelements having been deployed radially by axial withdrawal of theexternal casing,

FIG. 3 corresponds to FIGS. 1 and 2, with the carrier cylindersurrounded by positioning and anchoring feeler elements having beendeployed radially after axial withdrawal of the internal casing,

FIG. 4 is a lateral view of the carrier cylinder and the positioning andanchoring feeler elements,

FIG. 5 is a lateral perspective view of the positioning and anchoringfeeler elements,

FIG. 6 is a schematic face view of the inventive unit, and

FIG. 7 is a schematic lateral section of the variant.

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIG. 1, the present implementation example corresponds tothe medical problem, explained at the beginning, of implanting afunctioning replacement valve for the native aorta valve. The valveimplantation unit 10 comprises a carrier element 20 to hold the implant,joined to a plurality of feeler, or palpation, elements or fingers 30,31, here regularly spaced angularly all around, for positioning andanchoring relative to relief features, specifically a cavity in theaorta wall, unit 10 being linked removably to a positioning catheter 60.Unit 10 is associated with two concentric sleeves 41, 42 for successiveremote activation, by radial expansion, of feeler elements 30, 31 thenthe carrier element 20. The direction of movement of unit 10 istherefore towards the left in FIGS. 1 to 3. Reference 62 represents anaxis of symmetry and the drive direction of unit 10 and catheter 60.

The implantation valve forms a prosthesis 1 comprising valve units 2 ofthe valve whose shape and size correspond perfectly, in the operatingposition, to those of the native aorta valves 50 (FIG. 2). Theprosthesis 1 is fixed to the implant holding carrier vehicle element 20,here comprising a cylindrical mesh in a bio-compatible material such assteel, gold alloys and for preference as here, nitinol, which comprisesa shape memory nickel-titanium alloy offering the ability to regain itsshape after initial deformation, here by radial compression. The fixingof prosthesis 1 to the cylindrical nitinol mesh is made in well definedlocations leaving free those regions that correspond to the valve units2 after deployment from the stowed position of FIG. 2, as illustratedbelow in respect of FIG. 3.

FIG. 4 represents the cylindrical mesh 20 in the deployed form, carryingthe valve units 2 also deployed internally, on which are connected thefeeler elements 30, 31, here in the form of a generally cylindricalexterior ring of wire loops of which one (31) at least, here in factthree, protrudes laterally and towards the front, opposite the catheter60. In this example, the loops 31 extend, in the deployed position, in adirection inclined at about 30 degrees towards the front (direction ofmovement towards the target position) relative to the axis 62 of themesh 20 and the ring 30. The feeler elements 30, 31 are joined to thecylindrical mesh 20 in such a way that their axial and angular positionsrelative to it are perfectly defined. The assembly, cylindrical mesh 2and feeler elements 30, 31, is here composed of the auto expandablebio-compatible material mentioned above.

The cylindrical carrier mesh 20 is here covered with an impermeablelateral casing intended to be pressed against the aorta wall to avoidbypassing by the blood circulation.

FIG. 5 shows the feeler elements 30, 31 in perspective. FIG. 6 is aschematic view, along the unit 10 axial direction, showing the threeloops 31 protruding laterally from the tubular grid 20 that carriesthem, while the 2 valve units of the valve to be implanted are fixedinternally to the carrier cylinder 20.

In addition, if necessary, an inflatable balloon, joined to the catheter60, can here be placed inside the carrier cylinder 20, to be fed withliquid under pressure through catheter pipe 60 so as to cause or assistthe radial expansion of the carrier cylinder 20 to the required deployedform.

As the feeler elements 30, 31 are made in a self expanding material suchas nitinol, or an equivalent element forming an elastically protrudingfoot or finger, unit 10 is covered with an inhibition sleeve 42 to holdthe feeler elements 30, 31 in a stowed position, the loops 31 beingfolded on the ring 30 and thus also on the mesh 20. Sleeve 42 extends tocover the catheter 60. A second sleeve 41, effectively the same lengthand without effect on the feeler elements 30, 31, is here similarlyprovided to hold the carrier cylinder 20 in the stowed position, so asto avoid unplanned deployment even in the absence of inflation of theballoon 3. The two sleeves 41, 42, are mounted concentrically on thecatheter 60. The sleeves 41 and 42 are accessible from the end ofcatheter 60 opposite to the unit 10. Elements 3, 41, 42, and 60 comprisea functional catheter assembly separable from the unit 10, for thepositioning and switching on this latter and the payload (2).

The two sleeves 41, 42 inhibit the radial deployment or the structure20, 30, 31 until the latter reaches the region of the native aorta valve50 to be functionally replaced, and thus allow the introduction of unit10 into the blood circulation system, such as a reduced diameter incisedartery. As indicated, the catheter 60, with balloon 3, is detachablyjoined to the implantation unit 10 so as to allow an axial advance ofthe implantation unit 10 in the blood circulation system up to theimplantation location, and the withdrawal of the catheter assembly 3,41, 42, 60.

To free itself, the catheter 60 comprises, in this example, at the fixedend of carrier cylinder 20, a spring effect clamp (not shown), withremotely controlled teeth, fitted to rotate radially, for connection tothe unit 10 and has a sliding central remote control metal wire toaxially push back the claw branches or teeth so as to separate themradially and so free the catheter 60 of the implantation unit 10according to the sugar claw principle.

When the cylindrical mesh 20 is deployed, the pressure on the aortainternal wall is provided by the shape memory effect, which thus ensuresthe radial dilation of the prosthesis 1. The failed native valve unit 50is flattened by being pressed by the tubular grid 20 against the aortainternal wall, each of the three loops 31 protruding laterally havingpreviously been engaged in one, specifically, of the three native valveunits 50 and being similarly pressed to confirm its anchorage. The valveunits 50 are thus clamped between the mesh 20, 30 and the respectiveloops 31.

The implantation procedure for the unit 10 described above, according tothe preferred method of implementation, comprises the following steps.After insertion of the implantation unit 10 into the circulatory system,and after having pushed it using the catheter 60 to a position above thefinal target position, here precisely where the unit 10 arrives in theaorta, and so that a large diameter space is thus offered to it, thefollowing stage consists of freeing the lateral loops 31, initiallypressed against the stowed mesh 20, 30. The release of the loops 31 isdone by withdrawing the external retention sleeve 42 (FIG. 2), that isto say withdrawn whilst maintaining the thrust on the catheter 60. Theforward movement of the unit 10 continuing, the loops 31, being thenprotruded laterally towards the front with respect to the axialdirection of forward movement, in opposition to the catheter 60, theyform a sort of tripod and simultaneously penetrate the three respectivenative valves 50, effectively identical, comprising an arrangement ofconnection pockets in a complete ring with each extending over 120degrees, filling in total the whole of the perimeter of the aortainternal wall 51. Each native valve unit 50 offers a rounded base.

Each lateral protrusion 31, turned towards the front, presses againstthe base of the native valve unit 50 concerned, in general in a pointdistant from the “lowest” point of the base, that is to say, thefurthest from the catheter 60. This is therefore a partial stop becausethe axial advance of the unit 10 continues by thrust from the catheter60, the axial thrust of the unit 10 causing it to slide to the lowestpoint. The bottom of the valve unit 50 thus comprises a sort of inclinedplane guidance track (not orthogonal to the axis (62) of the aorta)which, in reaction to the axial forward force, creates a circumferentialreaction force causing the rotation of the unit 10 until the feeler loopconsidered 31 reaches the lowest point, which corresponds to a completeend wall (with tangential plane orthogonal to the axis (62) of the aorta51), and thus corresponds to the final axial and angular position soughtfor the unit 10.

Each lateral protrusion 31, with rounded ends, here as a loop, so as tobe able to slide in the bottom of the valve unit 50, thus comprises, bycontinuous cooperation with the variable depth rounded base of thenative valves 50, means for rotational drive of the feeler elements 30,31 and thus also of the cylindrical mesh 20, to which it is joined.However if the lateral protrusions 31 by chance bump against a nativevalve unit 50 commissure, the implantation unit 10 can be slightlywithdrawn and the operator twists the catheter 60 so that it pivotsangularly to be able to restart the positioning and anchoring operation.

The assembly, feeler elements 30, 31 and cylindrical mesh 20, beingpositioned axially and at an angle with respect to the specific reliefof the aorta comprising the native valve units 50, it is thenautomatically positioned with respect to the two coronary openings (52)for which the axial and angular position with respect to the valve units50 is determined and known, the valve unit—coronary axial distanceevidently depending on the size of the patient.

In the case considered here in which the three native valves 50 form acircular circumference to the aorta wall extending over 360 degrees, asingle lateral protrusion is sufficient to modulo 120 degreespositioning and anchoring the cylindrical mesh 20. As stated above, in ageneral case, there could only be one feeler 30, 31 working with a rowof cavities or pockets covering all the circumference of the tubularelement, or even a single pocket of cavity 50 only occupying a sector ofthe circumference and a plurality of feelers 30, 31 all around the unit10 so that one of them fits in the cavity.

It will be noted that, in the present example, modulo 120 degreespositioning can be tolerated because the two coronaries (52) naturallyeffectively show this angle. If this was not the case, it would benecessary laterally to enlarge two openings or serrations 22 provided inthe casing 21 so that they were positioned opposite the coronaries (52)(FIG. 4 and position marked on FIG. 3.), or again to feel, using thefeelers 31, the coronaries (52) themselves, which also comprise cavitiesin the aorta 51, and not to sense the native valve units 50. This casecorresponds to the variant described below.

Positioning thus having been effected, the following stage, as show inFIG. 3, consists of deploying the cylindrical mesh 20 carryinginternally the valve units 2 by withdrawing the internal retainingsleeve 41, to consolidate the anchorage and change the valve units 2 totheir operational form. For the clarity of the drawing, in particularthe protrusions 31, the mesh 20 has been represented with a relativelysmall diameter, whereas in fact it matches that of the aorta 51, with aslight increase to ensure the required lateral pressure. In the sameway, two protrusions 31 have been represented, although in fact they areseparated by 120 degrees, with the plane of FIG. 3 only in realitycutting one. For this reason, only a single coronary has been drawn(52).

The three loops 31 protruding however provide by themselves a basicanchorage in the bottom of the pockets comprising the native valves 50and ensure the positional stability of the prosthesis 1. After a fewweeks, fibrous tissue will cover the prosthesis 1, combining with thelateral protrusions 31 to further improve the fixing.

It will be noted however that, in the deployed position of the feelerelements 31, it is not necessary that their free ends should be firmlypressed against the aorta 51 wall. It is sufficient that their radialextension should be sufficient that they hook, in passing, onto thevalve units 50. Because of this, when the feeler elements 31 aredeployed, before the final position, the later axial translation of theunit 10, up to this position, is done without “hard” rubbing underpressure, of the part of the loops 31 on the aorta wall 51. The latterthus does not run any risk of damage due to scratching or piercing, theloops 31 being feelers, that follow the aorta wall 51 to detect thevalve units 50. As described above, rounded feet or lugs can also besuitable.

The feeler loops 31 thus do not here have very firm anchoring of theunit 10 in the aorta 51 as their main function, because they do not aimto exert a large radial anchoring pressure. As indicated above, this isonly a basic anchoring. It is then the radial deployment of the mesh 20that creates, by shape memory, a definitive radial anchoring pressurethat forces the mesh 20 under pressure against the aorta wall 51 andthus blocks any relative movement, such as the withdrawal of the unit 10that could be due to blood flow, in a direction opposite to theinsertion of the unit 10. The feeler elements 111 are then functionallysuperfluous. They however contribute to maintaining position by pinchingthe valve units 2. As the mesh offers a relatively high contact surfacewith the aorta 51, any risk of damaging the latter is excluded. Theshape memory material allows the radial pressure exerted on the aorta 51to be precisely determined, the diameter of the latter thus increasedbeing then perfectly defined, which eliminates all risk of excessiveradial stress.

The inventive procedure can be implemented in non-surgical manner andwithout therapeutic aims, to implant the unit 10 (or equivalent) in adetermined position in a tubular elements offering a wall including acavity, the procedure comprising the following stages:

a user inserts the unit (10) into an open end to the tubular element,

the user activates the drive means (60) (catheter, external magnet orother) to move the unit (10) up to a position upstream the determinedposition,

the user commands the feeler element (30, 31) activation means (42) and,the forward motion continuing,

the user stops the activation of the drive means (60) when he detects ablockage of the advance, due to the fact that the feeler means (30, 31)are positioned in the cavity.

To ease the drive of the unit 10, this one can be associated with a typeof precursor rostrum 61 (FIG. 1 to 3) forming a guide, in the form of acylindrical element of a limited diameter, joined to the catheter 60.

It will be noted that the implantation unit according to the inventioncan, first, be implanted alone, without implant or payload, the latterbeing implanted later on the implantation unit according to the sameprinciple. In a similar case, the inventive unit comprises means forreceiving the second support, to come, of the implant, said means beingarranged to ensure the positioning and anchorage, both axially, bystopping, and radially, with angular error correction means such as afinger or cavity provided to fit with an element of matching shape inthe second support.

In the variant shown in FIG. 7, the implantation unit has the reference110 and comprises functional elements similar to those of unit 10, withthe same references preceded by the hundred 1, which have not howeverall been represented, with the aim of clarity. The cylindrical carrierelement 120 is joined to a feeler element 131 which protrudes laterallyand which has the same type of construction as the carrier element 120.In precise fashion, the feeler element 131 appears in the form of acylinder, stowed radially in the rest position. When the unit 110 ispushed by the catheter 160, towards the bottom in FIG. 7, from aposition above that shown, it engages in the coronary 52 when the freeend is thus released from contact with the internal wall of the aorta51.

The unit 110 thus comprises a type of fork that locks by stopping in thebifurcation between the aorta 51 and the coronary 52. When the endposition is reached the two cylindrical elements 120, 131 are deployedby two balloons respectively and form a type of two fingered glove.

Thus, during the positioning phase, the feeler 131 presents a radiallystowed form, thus with reduced diameter not risking blocking thecoronary 52. Then the feeler 131 is deployed, by inflation of theassociated remote control balloon, and constitutes a lining, or internalcasing, pressed against the internal wall of the coronary 52 inaccordance with the principle explained above for the carrier cylinder20.

It will be noted that, as 120 and 131 each occupy a particular branch51, 52, they can be considered as functionally equivalent, with the twoprinciple functions if required. Each of them can in effect be a payload(2) carrier and can also be considered as being a feeler, because theaorta 51 can be considered (functionally in the context of the presentinvention) as being a cavity or branch with respect to the coronary 52.Thus the feeler means comprise a cylindrical element 131 arranged tochange from a stowed form to a radially deployed form, supported againsta wall of the cavity, here the coronary 52, under the influence ofremote control means (balloon and catheter 160),

To avoid the risks of movement of the feeler 131 into the couplingposition to the coronary 52, due to an angular error that necessitatesseveral attempts, it can be arranged for a guide wire to be passed intothe coronary 52 and the upper part of the aorta 51, the unit 110 beingthreaded above it across the feeler 131 that is thus angularly orientedtowards the coronary 52. Another guide wire can at the same time guidecylinder 120 into the aorta 51.

1. A device for implantation of a replacement heart valve, the devicecomprising: a carrier element having a tubular configuration, a firstend, and a second end, the carrier element being deployable from astowed position to a deployed position; and a plurality of feelerelements being deployable from a stowed position to a deployed position,at least a portion of each feeler element being disposed laterally aboutthe carrier element between the first end and the second end of thecarrier element, wherein the feeler elements are deployableindependently of the carrier element so as to protrude radiallyoutwardly relative to the carrier element.
 2. The device of claim 1,wherein in the stowed position of the feeler elements, at least aportion of each feeler element is substantially parallel to a lateralsurface portion of the carrier element.
 3. The device of claim 1,wherein in the stowed position of the feeler elements, the feelerelements fold alongside a lateral surface portion of the carrierelement.
 4. The device of claim 1, wherein in the deployed position ofthe carrier element and the deployed position of the feeler elements,the feeler elements fold alongside a lateral surface portion of thecarrier element.
 5. The device of claim 1, wherein the feeler elementshave a configuration sufficient for the feeler elements to be receivedby a respective pocket defined between a respective valve leaflet and awall of a blood vessel and have a length sufficient to extendsubstantially from a base of the respective pocket where the respectivevalve leaflet meets the wall of the blood vessel to at least a free endof the respective valve leaflet.
 6. The device of claim 1, furthercomprising a valve prosthesis carried by the carrier element.
 7. Thedevice of claim 1, wherein the feeler elements have a rounded free end.8. The device of claim 1, wherein the plurality of feeler elements areconnected to each other to form a ring that is disposed around thecarrier element.
 9. The device of claim 1, wherein the plurality offeeler elements are angularly spaced from each other about the carrierelement.
 10. The device of claim 1, wherein the carrier elementcomprises a tubular mesh.
 11. The device of claim 1, further comprisinga casing covering the carrier element.
 12. The device of claim 1,wherein the carrier element and the feeler elements are self-expandable.13. The device of claim 1, wherein at least one of the carrier elementand the feeler elements comprises nitinol.
 14. The device of claim 1,wherein the feeler elements are deployable independently of the carrierelement so as to protrude radially outwardly relative to the carrierelement and extend at an acute angle relative to a longitudinal axis ofthe carrier element.
 15. The device of claim 1, wherein the feelerelements are deployable independently of the carrier element so as toprotrude radially outwardly relative to the carrier element such that,in a lateral cross-sectional plane through the carrier element and arespective feeler element, a surface of the respective feeler elementsubstantially facing the carrier element is disposed at an acute anglerelative to an outer lateral surface of the carrier element.
 16. Thedevice of claim 1, wherein, in the stowed position of the carrierelement, the carrier element is configured to be received in a firstsleeve, and in the stowed position of the feeler elements, the feelerelements are configured to be received within a second sleeveconcentrically disposed about the first sleeve.
 17. The device of claim16, wherein the carrier element and the feeler elements are configuredto be respectively placed in the deployed position by respectivelyremoving the feeler elements from the second sleeve and the carrierelement from the first sleeve.
 18. The device of claim 16, wherein thefeeler elements and the carrier element are sequentially deployable bysequentially removing the feeler elements from the second sleeve and thecarrier element from the first sleeve.
 19. The device of claim 1,wherein the carrier element is deployable from the stowed position tothe deployed position via an inflatable balloon.
 20. The device of claim1, wherein the feeler elements extend from a connected end to a free endin a direction having a component generally parallel to a longitudinalaxis of the carrier element in the deployed position.
 21. The device ofclaim 1, wherein the feeler elements have a respective free ends thatare generally U-shaped or generally V-shaped.
 22. The unit of claim 1,wherein the carrier element and the feeler elements are configured tograsp respective valve leaflets between the carrier element and thefeeler elements in the deployed position of the carrier element and thefeeler elements.
 23. A device for implantation of a replacement heartvalve, comprising: a carrier element having a tubular configuration, afirst end, and a second end, the carrier element being deployable from astowed position to a deployed position; and a plurality of feelerelements deployable from a stowed position to a deployed position,wherein the plurality of feeler elements are deployable independently ofthe carrier element so as to protrude radially outwardly relative to thecarrier element such that, in a lateral cross-sectional plane throughthe carrier element and a respective feeler element, a surface of therespective feeler element substantially facing the carrier element isdisposed at an acute angle relative to an outer lateral surface of thecarrier element.
 24. The device of claim 23, further comprising a valveprosthesis carried by the carrier element.
 25. The device of claim 23,wherein the plurality of feeler elements are connected to each other toform a ring that is disposed around the carrier element.
 26. The deviceof claim 23, wherein the plurality of feeler elements are angularlyspaced from each other about the carrier element.
 27. The device ofclaim 23, wherein the carrier element comprises a tubular mesh.
 28. Thedevice of claim 23, further comprising a casing covering the carrierelement.
 29. The device of claim 23, wherein the carrier element and thefeeler elements are self-expandable.
 30. The device of claim 23, whereinat least one of the carrier element and the feeler elements comprisesnitinol.
 31. The device of claim 23, wherein, in the stowed position ofthe carrier element, the carrier element is configured to be received ina first sleeve, and in the stowed position of the feeler elements, thefeeler elements are configured to be received within a second sleeveconcentrically disposed about the first sleeve.
 32. The device of claim31, wherein the carrier element and the feeler elements are configuredto be respectively placed in the deployed position by respectivelyremoving the feeler elements from the second sleeve and the carrierelement from the first sleeve.
 33. The device of claim 31, wherein thefeeler elements and the carrier element are sequentially deployable bysequentially removing the feeler elements from the second sleeve and thecarrier element from the first sleeve.
 34. The device of claim 23,wherein the carrier element is deployable from the stowed position tothe deployed position via an inflatable balloon.
 35. The device of claim23, wherein the feeler elements have respective rounded free ends. 36.The device of claim 23, wherein the feeler elements have respective freeends that are generally U-shaped or generally V-shaped.
 37. The unit ofclaim 23, wherein the carrier element and the feeler elements areconfigured to grasp respective valve leaflets between the carrierelement and the feeler elements in the deployed position of the carrierelement and the feeler elements.
 38. The device of claim 23, wherein, inthe deployed position, the feeler elements are configured to bepositioned at least partially within respective cavities defined betweenrespective valve leaflets and a wall supporting the valve leaflets. 39.A unit for implantation, comprising: a deployable carrier elementconfigured to be positioned on a first side of valve leaflets of a heartvalve; and a plurality of feeler elements connected to the carrierelement and configured to be respectively positioned at least partiallywithin a cavity defined between a respective valve leaflet and a wallsupporting the respective valve leaflet, the plurality of feelerelements being configured to be disposed on a second side of therespective valve leaflets, opposite the first side.
 40. The unit ofclaim 39, wherein the feeler elements are deployable from a stowedposition in which the feeler elements are folded alongside the carrierelement to a deployed position laterally spaced from the carrierelement.
 41. The unit of claim 39, wherein at least a portion of thefeeler elements surround at least a portion of the carrier element. 42.The unit of claim 39, wherein the carrier element and the feelerelements are self-expandable.
 43. The unit of claim 39, furthercomprising a valve prosthesis carried by the carrier element.
 44. Theunit of claim 39, wherein the carrier element and the feeler elementsare configured to grasp the respective valve leaflets between thecarrier element and the feeler elements in the deployed position of thecarrier element and the feeler elements.
 45. A system for implantationof a replacement heart valve, the system comprising: a valve prosthesis;a carrier element having a first end and a second end and configured tosupport the valve prosthesis, the carrier element being deployable froma stowed position to a deployed position; and a plurality of feelerelements being deployable from a stowed position to a deployed position,at least a portion of each feeler element being disposed laterally aboutthe carrier element between the first end and the second end of thecarrier element, wherein the feeler elements are deployableindependently of the carrier element so as to protrude radiallyoutwardly relative to the carrier element.
 46. The system of claim 45,wherein the plurality of feeler elements are connected to each other toform a ring that is disposed around the carrier element.
 47. The systemof claim 45, wherein the carrier element has a tubular configuration andthe plurality of feeler elements are angularly spaced from each otherabout the carrier element.
 48. The system of claim 45, wherein thecarrier element comprises a tubular mesh.
 49. The system of claim 45,wherein the carrier element is configured to support the valveprosthesis during delivery of the carrier element to a heart valve forreplacement.
 50. The system of claim 45, wherein the carrier element andthe valve prosthesis are configured to be delivered separately to aheart valve for replacement.
 51. The system of claim 45, wherein thevalve prosthesis is configured to be deployable to an operational formwhen the carrier element is in the deployed position.
 52. The system ofclaim 45, wherein the carrier element and the feeler elements areself-expandable.
 53. The system of claim 45, wherein at least one of thecarrier element and the feeler elements comprises nitinol.
 54. Thesystem of claim 45, wherein the feeler elements have a configurationsufficient for the feeler elements to be respectively received inpockets defined between respective valve leaflets and a wall of a bloodvessel and have a length sufficient to extend substantially from a baseof the pockets where the respective valve leaflet meets the wall of theblood vessel to at least a free end of the respective valve leaflet. 55.A system for implantation of a replacement heart valve, the systemcomprising: a valve prosthesis; a carrier element having a first end anda second end and configured to support the valve prosthesis, the carrierelement being deployable from a stowed position to a deployed position;and a plurality of feeler elements deployable from a stowed position toa deployed position, wherein the plurality of feeler elements aredeployable independently of the carrier element so as to protruderadially outwardly relative to the carrier element such that, in alateral cross-sectional plane through the carrier element and arespective feeler element, a surface of the respective feeler elementsubstantially facing the carrier element is disposed at an acute anglerelative to an outer lateral surface of the carrier element.
 56. Thesystem of claim 55, wherein the carrier element has a tubularconfiguration and the plurality of feeler elements are angularly spacedfrom each other about the carrier element.
 57. The system of claim 55,wherein the carrier element comprises a tubular mesh.
 58. The system ofclaim 55, wherein the carrier element is configured to support the valveprosthesis during delivery of the carrier element to a heart valve forreplacement.
 59. The system of claim 55, wherein the carrier element andthe valve prosthesis are configured to be delivered separately to aheart valve for replacement.
 60. The system of claim 55, wherein thevalve prosthesis is configured to be deployable to an operational formwhen the carrier element is in the deployed position.
 61. The system ofclaim 55, wherein the carrier element and the feeler elements areself-expandable.
 62. The system of claim 55, wherein at least one of thecarrier element and the feeler elements comprises nitinol.
 63. Thesystem of claim 55, wherein the feeler elements have a configurationsufficient for the feeler elements to be respectively received inpockets defined between respective valve leaflets and a wall of a bloodvessel and have a length sufficient to extend substantially from a baseof the pockets where the respective valve leaflet meets the wall of theblood vessel to at least a free end of the respective valve leaflet.